Evidence and evidence gaps of medical treatment of non-tumorous diseases of the head and neck.

Unfortunately, the treatment of numerous otolaryngological diseases often lacks of evidence base because appropriate studies are missing. Whereas sufficient high-quality trials exist for the specific immunotherapy of allergic rhinitis and in a limited measure also for the angiotensin-converting enzyme inhibitor induced angioedema, the evidence for Menière's disease or for pharmacotherapy of postoperative laryngeal edema is rather poor. This contribution will discuss the trial situation and evidence of the respective diseases.